Cavitary tissue ablation

ABSTRACT

The invention relates to a tissue ablation system including an ablation device having a deployable applicator head configured to be delivered to a tissue cavity and ablate marginal tissue surrounding the tissue cavity. The deployable applicator head is configured to be delivered to a tissue cavity while in a collapsed configuration and ablate marginal tissue surrounding the tissue cavity while in an expanded configuration.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional applicationSer. No. 15/142,616, filed Apr. 29, 2016, which claims the benefit of,and priority to, U.S. Provisional Application Ser. No. 62/154,377, filedApr. 29, 2015, the contents of which are hereby incorporated byreference herein in their entirety.

FIELD

The present disclosure relates generally to medical devices, and, moreparticularly, to a tissue ablation device having a deployable applicatorhead configured to be delivered to a tissue cavity and ablate marginaltissue surrounding the tissue cavity.

BACKGROUND

Cancer is a group of diseases involving abnormal cell growth with thepotential to invade or spread to other parts of the body. Cancergenerally manifests into abnormal growths of tissue in the form of atumor that may be localized to a particular area of a patient's body(e.g., associated with a specific body part or organ) or may be spreadthroughout. Tumors, both benign and malignant, are commonly treated andremoved via surgical intervention, as surgery often offers the greatestchance for complete removal and cure, especially if the cancer has notspread to other parts of the body. However, in some instances, surgeryalone is insufficient to adequately remove all cancerous tissue from alocal environment.

For example, treatment of early stage breast cancer typically involves acombination of surgery and adjuvant irradiation. Unlike a mastectomy, alumpectomy removes only the tumor and a small rim (area) of the normaltissue around it. Radiation therapy is given after lumpectomy in anattempt to eradicate cancer cells that may remain in the localenvironment around the removed tumor, so as to lower the chances of thecancer returning. However, radiation therapy as a post-operativetreatment suffers various shortcomings. For example, radiationtechniques can be costly and time consuming, and typically involvemultiple treatments over weeks and sometimes months. Furthermore,radiation often results in unintended damage to the tissue outside thetarget zone. Thus, rather than affecting the likely residual tissue,typically near the original tumor location, radiation techniques oftenadversely affect healthy tissue, such as short and long-termcomplications affecting the skin, lungs, and heart. Accordingly, suchrisks, when combined with the burden of weeks of daily radiation, maydrive some patients to choose mastectomy instead of lumpectomy.Furthermore, some women (e.g., up to thirty percent (30%)) who undergolumpectomy stop therapy before completing the full treatment due to thedrawbacks of radiation treatment. This may be especially true in ruralareas, or other areas in which patients may have limited access toradiation facilities.

SUMMARY

Tumors, both benign and malignant, are commonly treated and destroyedvia surgical intervention, as surgery often offers the greatest chancefor complete removal and cure, especially if the cancer has notmetastasized. However, after the tumor is destroyed, a hollow cavity mayremain, wherein tissue surrounding this cavity and surrounding theoriginal tumor site can still leave abnormal or potentially cancerouscells that the surgeon fails, or is unable, to excise. This surroundingtissue is commonly referred to as “margin tissue” or “marginal tissue”,and is the location within a patient where a reoccurrence of the tumormay most likely occur.

The tissue ablation system of the present disclosure can be used duringan ablation procedure to destroy the thin rim of marginal tissue aroundthe cavity in an effort to manage residual disease in the localenvironment that has been treated. In particular, the present disclosureis generally directed to a cavitary tissue ablation system including anablation device to be delivered into a tissue cavity and emitnon-ionizing radiation, such as radiofrequency (RF) energy, to treat themarginal tissue around the tissue cavity. The ablation device generallyincludes a probe having a deployable applicator member or head coupledthereto and configured to transition between a collapsed configuration,in which the applicator head can be delivered to and maneuvered within apreviously formed tissue cavity (e.g., formed from tumor removal), andan expanded configuration, in which the applicator head is configured toablate marginal tissue (via RF) immediately surrounding the site of asurgically removed tumor in order to minimize recurrence of the tumor.The tissue ablation device of the present disclosure is configured toallow surgeons, or other medical professionals, to deliver precise,measured doses of RF energy at controlled depths to the marginal tissuesurrounding the cavity.

Accordingly, a tissue ablation device consistent with the presentdisclosure may be well suited for treating hollow body cavities, such asirregularly-shaped cavities in breast tissue created by a lumpectomyprocedure. It should be noted, however, that the devices of the presentdisclosure are not limited to such post-surgical treatments and, as usedherein, the phrase “body cavity” may include non-surgically createdcavities, such as natural body cavities and passages, such as the ureter(e.g. for prostate treatment), the uterus (e.g. for uterine ablation orfibroid treatment), fallopian tubes (e.g. for sterilization), and thelike. Additionally, or alternatively, tissue ablation devices of thepresent disclosure may be used for the ablation of marginal tissue invarious parts of the body and organs (e.g., skin, lungs, liver,pancreas, etc.) and is not limited to treatment of breast cancer.

In one aspect, a tissue ablation device consistent with the presentdisclosure includes a dual-balloon design. For example, the tissueablation device includes a probe including a nonconductive elongatedshaft having a proximal end and a distal end and at least one lumenextending therethrough, and an expandable balloon assembly coupled tothe distal end of the probe shaft. The expandable balloon assemblyincludes an expandable inner balloon having an inner balloon wall havingan exterior surface, an interior surface and a lumen defined therein andin fluid connection with at least one lumen of the probe. The innerballoon is configured to inflate into an expanded configuration inresponse to delivery of a first fluid from at least one lumen of theprobe into the lumen of the inner balloon.

The expandable balloon assembly further includes an expandable outerballoon surrounding the inner balloon and configured to transition to anexpanded configuration in response expansion of the inner balloon. Theouter balloon includes an outer balloon wall having an interior surface,an exterior surface, and a chamber defined between the interior surfaceof the outer balloon and the exterior surface of the inner balloon. Theexterior surface of the inner balloon wall has an irregular surfacedefined thereon. In particular, the inner balloon wall may include aplurality of bumps, ridges, or other features arranged on an outersurface thereof configured to maintain separation between the outersurface of the inner balloon wall and the interior surface of the outerballoon wall, thereby ensuring the chamber is maintained.

The chamber defined between the inner surface of the outer balloon walland the outer surface of the inner balloon wall is in fluid connectionwith at least one lumen of the probe, so as to receive a second fluidtherefrom. The outer balloon wall further includes a plurality ofperforations configured to allow the passage of the second fluid fromthe chamber to the exterior surface of the outer balloon upon deliveryof the second fluid from at least one lumen of the probe into thechamber.

The ablation device further includes an electrode array comprising aplurality of conductive wires positioned within the chamber between theexterior surface of the inner balloon wall and the interior surface ofthe outer balloon wall. Each of the plurality of conductive wires isconfigured to conduct energy to be carried by the second fluid withinthe chamber from the interior surface to the exterior surface of theouter balloon wall for ablation of a target tissue. In particular, uponactivating delivery of RF energy from the at least one conductiveelement, the RF energy is transmitted from the conductive element to theexterior surface of the outer balloon by way of fluid weeping from theperforations, thereby creating a virtual electrode. For example, thefluid within the chamber and weeping through the perforations on theouter balloon is a conductive fluid (e.g., saline) and thus able tocarry electrical current from an active conductive element. Upon thefluid weeping through the perforations, a pool or thin film of fluid isformed on the exterior surface of the outer balloon and is configured toablate surrounding tissue via the electrical current carried from theactive conductive elements. Accordingly, ablation via RF energy is ableto occur on the exterior surface of the outer balloon in a controlledmanner and does not require direct contact between tissue and theconductive elements.

In some embodiments, each of the plurality of conductive wires isindependent from one another. Thus, in some embodiments, each of theplurality of conductive wires, or one or more sets of a combination ofconductive wires, is configured to independently receive an electricalcurrent from an energy source and independently conduct energy. In someembodiments, each of the plurality of conductive wires is configured toconduct energy upon receipt of the electrical current, the energyincluding RF energy.

In some embodiments, the irregular surface defined on the exteriorsurface of the inner balloon wall may include a plurality of ridges. Theplurality of ridges may generally extend longitudinally along theexterior surface of the inner balloon wall. The plurality of ridges maybe configured to make contact with the inner surface of the outerballoon wall to maintain separation between the remaining outer surfaceof the inner balloon wall and the inner surface of the outer balloonwall. Each of the plurality of conductive wires may further bepositioned between two adjacent ridges and one or more of the pluralityof perforations of the outer balloon wall may be substantially alignedwith an associated one of the plurality of conductive wires.

In some embodiments, the inner balloon may be configured to receive thefirst fluid from a first lumen of the probe and the outer balloon may beconfigured to receive the second fluid from a second lumen of the probe.The delivery of the first and second fluids to the inner and outerballoons, respectively, may be independently controllable via acontroller, for example. In some embodiments, the first and secondfluids are different. In other embodiments, the first and second fluidsare the same. In some embodiments, at least the second fluid, which isto be delivered to the chamber and used for creating a virtual electrodein combination with the electrode array, is a conductive fluid, such assaline.

The dual-balloon design is particularly advantageous in that it does notrequire a syringe pump, and can be supplied with gravity-fed fluidsource. In addition, the volume of fluid required within the chamber issignificantly less (when compared to a single balloon design), thus lesswattage is required to achieve RF ablation.

In another aspect, a tissue ablation device consistent with the presentdisclosure includes an expandable mesh body configured to deliver energyfor tissue ablation. The tissue ablation device includes a probecomprising an elongated shaft having a proximal end and a distal end andat least one lumen providing a pathway extending from the proximal endto the distal end and an expandable mesh assembly coupled to the distalend of the probe. The mesh assembly includes a self-expanding mesh bodyconfigured to transition between a collapsed configuration and anexpanded configuration. When in the collapsed configuration, the meshbody is received within the at least one lumen of the probe and when inthe expanded configuration, the mesh body is deployed from the at leastone lumen of the probe and expands into a predefined shape. The meshbody is comprised of an electrically conductive material and configuredto conduct and deliver electrical current to target tissue when in theexpanded configuration.

In some embodiments, the self-expanding mesh body includes a webbingcoating one or more portions of the mesh body, wherein the web comprisesa non-conductive material. The webbing is configured to block deliveryof electrical current from the one or more portions of mesh body coatedwith the webbing.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the claimed subject matter will be apparentfrom the following detailed description of embodiments consistenttherewith, which description should be considered with reference to theaccompanying drawings, wherein:

FIG. 1 is a schematic illustration of an ablation system consistent withthe present disclosure.

FIGS. 2A-2C are perspective views of an exemplary embodiment of a tissueablation device including an expandable applicator head configured totransition between collapsed and expanded configurations and to ablatemarginal tissue;

FIG. 3 is a perspective view, partly in section, of one embodiment of anapplicator head compatible with the tissue ablation device of FIG. 1;

FIG. 4 is a perspective view of another embodiment of an applicator headcompatible with the tissue ablation device of FIG. 1;

FIG. 5 is an exploded view of the applicator head of FIG. 4;

FIG. is a perspective view, partly in section, of the applicator head ofFIG. 4;

FIGS. 7A and 7B are sectional views of a portion of the applicator headof FIG. 6 illustrating the arrangement of components relative to oneanother;

FIG. 8 is a schematic illustration of the delivery of the applicatorhead of FIG. 3 into a tissue cavity and subsequent ablation of marginaltissue according to methods of the present disclosure;

FIG. 9 is a perspective view of another embodiment of an applicator headcompatible with the tissue ablation device of FIG. 1;

FIG. 10 illustrates a method of deploying the applicator head of FIG. 9into an expanded configuration for delivery of RF energy to a targetsite for ablation of marginal tissue;

FIG. 11 illustrates different embodiments of the outer surface of theapplicator head of FIG. 9; and

FIG. 12 is a schematic illustration of the delivery of the applicatorhead of FIG. 9 into a tissue cavity and subsequent ablation of marginaltissue according to methods of the present disclosure.

For a thorough understanding of the present disclosure, reference shouldbe made to the following detailed description, including the appendedclaims, in connection with the above-described drawings. Although thepresent disclosure is described in connection with exemplaryembodiments, the disclosure is not intended to be limited to thespecific forms set forth herein. It is understood that various omissionsand substitutions of equivalents are contemplated as circumstances maysuggest or render expedient.

DETAILED DESCRIPTION

By way of overview, the present disclosure is generally directed to atissue ablation device having a deployable applicator head configured tobe delivered into a tissue cavity and ablate marginal tissue surroundingthe tissue cavity.

The tissue ablation system of the present disclosure can be used duringan ablation procedure to destroy the thin rim of marginal tissue aroundthe cavity in an effort to manage residual disease in the localenvironment that has been treated. In particular, the present disclosureis generally directed to a cavitary tissue ablation system including anablation device to be delivered into a tissue cavity and emitnon-ionizing radiation, such as radiofrequency (RF) energy, to treat themarginal tissue around the tissue cavity. The ablation device generallyincludes a probe having a deployable applicator head coupled thereto andconfigured to transition between a collapsed configuration, in which theapplicator head can be delivered to and maneuvered within a previouslyformed tissue cavity (e.g., formed from tumor removal), and an expandedconfiguration, in which the applicator head is configured to ablatemarginal tissue (via RF) immediately surrounding the site of asurgically removed tumor in order to minimize recurrence of the tumor.The tissue ablation device of the present disclosure is configured toallow surgeons, or other medical professionals, to deliver precise,measured doses of RF energy at controlled depths to the marginal tissuesurrounding the cavity.

Accordingly, a tissue ablation device consistent with the presentdisclosure may be well suited for treating hollow body cavities, such asirregularly-shaped cavities in breast tissue created by a lumpectomyprocedure. It should be noted, however, that the devices of the presentdisclosure are not limited to such post-surgical treatments and, as usedherein, the phrase “body cavity” may include non-surgically createdcavities, such as natural body cavities and passages, such as the ureter(e.g. for prostate treatment), the uterus (e.g. for uterine ablation orfibroid treatment), fallopian tubes (e.g. for sterilization), and thelike. Additionally, or alternatively, tissue ablation devices of thepresent disclosure may be used for the ablation of marginal tissue invarious parts of the body and organs (e.g., skin, lungs, liver,pancreas, etc.) and is not limited to treatment of breast cancer.

FIG. 1 is a schematic illustration of an ablation system 10 forproviding ablation of marginal tissue during a tumor removal procedurein a patient 12. The ablation system 10 generally includes an ablationdevice 14, which includes a probe having a deployable applicator memberor head 16 and an elongated catheter shaft 17 to which the deployableapplicator head 16 is connected. The catheter shaft 17 may generallyinclude a nonconductive elongated member including a fluid deliverylumen. The ablation device 14 may further be coupled to a devicecontroller 18 and an ablation generator 20 over an electricalconnection, and an irrigation pump or drip 22 over a fluid connection.As will be described in greater detail herein, the device controller 18may be used to control the emission of energy from one or moreconductive elements of the device 14 to result in ablation, as well ascontrolling the delivery of fluid to or from the deployable applicatorhead 16 so as to control the expansion and collapse of the head 16. Insome cases, the device controller 18 may be housed within the ablationdevice 14. The ablation generator 20 may also connected to a returnelectrode 15 that is attached to the skin of the patient 12.

As will be described in greater detail herein, during an ablationtreatment, the ablation generator 20 may generally provide RF energy(e.g., electrical energy in the radiofrequency (RF) range (e.g., 350-800kHz)) to an electrode array of the ablation device 14, as controlled bythe device controller 18. At the same time, saline may also be releasedfrom the head 16. The RF energy travels through the blood and tissue ofthe patient 12 to the return electrode 15 and, in the process, ablatesthe region(s) of tissues adjacent to portions of the electrode arraythat have been activated.

Turning to FIGS. 2A-2C, one embodiment of an exemplary tissue ablationdevice configured to ablate marginal tissue is shown. The tissueablation devices of the present disclosure generally include a probeincluding a shaft 17 having a proximal end and a distal end, wherein theapplicator head 16 is positioned at the distal end. In some embodiments,the shaft 17 of the probe may generally resemble a catheter and thus mayfurther include at least one lumen for providing a pathway from theproximal end of the shaft to the distal end of the shaft and theapplicator head so as to allow various components to be in fluidcommunication with the applicator head.

For example, in one embodiment, the applicator head includes at leastone balloon configured to transition from a collapsed configuration toan expanded configuration in response to delivery of a fluid thereto.FIGS. 2A-2C illustrate the applicator head 16 transitioning from acollapsed configuration (FIG. 2A) to an expanded configuration (FIG. 2B)via delivery of a fluid to the head 16 and activated to emit energy forablation of tissue (FIG. 2C). The at least one lumen of the shaft 17 mayprovide a fluid pathway from the proximal end, which may be coupled to afluid source (i.e., irrigation pump or drip 22), and the interior volumeof the balloon 16. Furthermore, as will be described in greater detailherein, the tissue ablation devices of the present disclosure furtherinclude a conductive element 19 (e.g., an electrode) positioned withinthe applicator head 16 and configured to deliver RF energy for theablation of marginal tissue. Accordingly, the probe may be coupled to anRF generator 20, for example, by way of an electrical connection at theproximal end, and wiring may pass through the at least one lumen of theshaft 17 to the conductive element 19. Further, in another embodiment,the applicator head may include a self-expanding mesh-like conductiveelement configured to deliver RF energy upon delivery to the targetsite. Accordingly, one or more control wires or other components may becoupled to the mesh-like conductive element to control the retractionand expansion (e.g., via pushing and pulling) of the mesh-likeconductive element from the shaft of the probe, as well as electricalwiring for electrically coupling the conductive element and RFgenerator, wherein such control and electrical wires may be housedwithin the at least one lumen of the shaft of the probe.

Accordingly, in some embodiments, the shaft 17 of the probe may beconfigured as a handle adapted for manual manipulation. It should benoted, however, that in other embodiments, the shaft may be configuredfor connection to and/or interface with a surgical robot, such as the DaVinci® surgical robot available from Intuitive Surgical, Inc.,Sunnyvale, Calif. In all cases, the shaft may be configured to be heldin place by a shape lock or other deployment and suspension system ofthe type that is anchored to a patient bed and which holds the probe inplace while the ablation or other procedure takes place, eliminating theneed to a user to manually hold the device for the duration of thetreatment.

FIG. 3 is a perspective view, partly in section, of one embodiment of anapplicator head 100 compatible with the tissue ablation device 14 ofFIG. 1. As shown, the applicator head 100 includes an inflatable balloon102 having a plurality of perforations 104, holes, or micropores, so asto allow a fluid provided within the balloon 102, such as saline, topass therethrough, or weep, from the balloon 102 when the balloon 102 isinflated. The perforations 104 may be sized, shaped, and/or arranged insuch a pattern so as to allow a volume of fluid to pass from theinterior volume of the balloon to an exterior surface of the balloon ata controlled rate so as to allow the balloon to remain inflated andmaintain its shape.

As previously described, the probe further includes a conductive element106, such as an electrode, positioned within the balloon, wherein theelectrode 106 is coupled to an RF energy source 20. When in thecollapsed configuration (e.g., little or no fluid within the interiorvolume) (shown in FIG. 2A), the balloon has a smaller size or volumethan when the balloon is in the expanded configuration. Once positionedwithin the target site (e.g., tissue cavity), fluid may then bedelivered to the balloon so as to inflate the balloon into an expandedconfiguration (shown in FIG. 2B), at which point, ablation of marginaltissue can occur. In particular, an operator (e.g., surgeon) mayinitiate delivery of RF energy from the conductive element 106 by usingthe controller 18, and RF energy is transmitted from the conductiveelement 106 to the outer surface of the balloon 102 by way of the fluidweeping from the perforations 104. Accordingly, ablation via RF energyis able to occur on the exterior surface (shown in FIG. 2C). Morespecifically, upon activating delivery of RF energy from the conductiveelement (electrode), the RF energy is transmitted from the conductiveelement to the outer surface of the balloon by way of the fluid weepingfrom the perforations, thereby creating a virtual electrode. Forexample, the fluid within the interior of the balloon 102 and weepingthrough the perforations 104 to the outer surface of the balloon 102 isa conductive fluid (e.g., saline) and thus able to carry electricalcurrent from the active electrode 106. Accordingly, upon the fluidweeping through the perforations 104, a pool or thin film of fluid isformed on the exterior surface of the balloon 102 and is configured toablate surrounding tissue via the electrical current carried from theactive electrode 106. Accordingly, ablation via RF energy is able tooccur on the exterior surface of the balloon in a controlled manner anddoes not require direct contact between tissue and the electrode 106.

FIG. 4 is a perspective view of another embodiment of an applicator head200 compatible with the tissue ablation device 14 and FIG. 5 is anexploded view of the applicator head 200 of FIG. 4. As shown, theapplicator head 200 includes a multiple-balloon design. For example, theapplicator head 200 includes an inner balloon 202 coupled to a firstfluid source via a first fluid line 24 a and configured to inflate intoan expanded configuration in response to the delivery of fluid (e.g.,saline) thereto. The applicator head 200 further includes an outerballoon 204 surrounding the inner balloon 202 and configured tocorrespondingly expand or collapse in response to expansion or collapseof the inner balloon 202.

The inner balloon 202 may include an irregular outer surface 208, whichmay include a plurality of bumps, ridges, or other features, configuredto maintain separation between the outer surface of the inner balloon202 and an interior surface of the outer balloon 204, thereby ensuringthat a chamber is maintained between the inner and outer balloons. Theouter balloon 204 may be coupled to a second fluid source (or the firstfluid source) via a second fluid line 24 b. The outer balloon 204 mayfurther include a plurality of perforations or holes 210 so as to allowfluid from the second fluid source to pass therethrough, or weep, fromthe outer balloon 204. The perforations may be sized, shaped, and/orarranged in such a pattern so as to allow a volume of fluid to pass fromthe chamber to an exterior surface of the outer balloon at a controlledrate.

The applicator head 200 further includes one or more conductiveelements, generally resembling electrically conductive wires or tines206, positioned within the chamber area between the inner balloon 202and outer balloon 204. The conductive elements 206 are coupled to the RFgenerator 20 via an electrical line 26, and configured to conductelectrical current to be carried by the fluid within the chamber fromthe interior surface to the exterior surface of the outer balloon 204for ablation of a target tissue, as will be described in greater detailherein. It should be noted that in one embodiment, the plurality ofconductive wires 206 may be electrically isolated and independent fromone another. This design allows for each conductive wire to receiveenergy in the form of electrical current from a source (e.g., RFgenerator) and emit RF energy in response. The system may include adevice controller 18, for example, configured to selectively control thesupply of electrical current to each of the conductive wires 206.

FIG. 6 is a perspective view, partly in section, of the applicator head200 illustrating compatible with the tissue ablation device of FIG. 1.FIGS. 7A and 7B are sectional views of a portion of the applicator head200 illustrating the arrangement of components relative to one another.

As shown in FIG. 6, the inner and outer balloons include a chamber 214defined there between. In particular, the plurality of bumps or ridges208 arranged on an outer surface of the inner balloon 202 are configuredto maintain separation between the outer surface of the inner balloon202 and an interior surface of the outer balloon 204, thereby ensuringthe chamber 214 is maintained.

Once positioned within the target site, a first fluid may be deliveredto a lumen 212 of the inner balloon 202, so as to inflate the innerballoon 202 into an expanded configuration, at which point, the outerballoon 204 further expands. A second fluid may then be delivered to theouter balloon 204 such that the second fluid flows within the chamber214 between the inner and outer balloons 202, 204 and weeps from theouter balloon 204 via the perforations 210. Upon activating delivery ofRF energy from the conductive elements 206, the RF energy is transmittedfrom the conductive elements 206 to the outer surface of the outerballoon 204 by way of the fluid weeping from the perforations 210,thereby creating a virtual electrode. For example, the fluid within thechamber 214 and weeping through the perforations 210 on the outerballoon 204 is a conductive fluid (e.g., saline) and thus able to carryelectrical current from the active conductive elements 206. Accordingly,upon the fluid weeping through the perforations 210, a pool or thin filmof fluid is formed on the exterior surface of the outer balloon 204 andis configured to ablate surrounding tissue via the electrical currentcarried from the active conductive elements 206. Accordingly, ablationvia RF energy is able to occur on the exterior surface of the outerballoon 204 in a controlled manner and does not require direct contactbetween tissue and the conductive elements 206.

This embodiment is particularly advantageous in that the dual-balloondesign does not require a syringe pump, and can be supplied withgravity-fed fluid source 22. In addition, the volume of fluid requiredwithin the chamber is significantly less (when compared to a singleballoon design), thus less wattage is required to achieve RF ablation.Another advantage of the dual-balloon design of applicator head 200 isthat it is not limited to placement within tissue cavities. Rather, whenin a collapsed state, the applicator head 200 is shaped and/or sized tofit through working channels of scopes or other access devices, forexample, and thus be used for ablation in a plurality of locationswithin the human body.

It should be further noted that the device 14 of the present disclosure,including the applicator head 200, may further be equipped with feedbackcapabilities. For example, while in a deflated, collapsed configuration,and prior to saline flow, the head 200 may be used for the collection ofinitial data (e.g., temperature and conductivity measurements (impedancemeasurements) from one or more of the conductive elements 206. Then,upon carrying out the ablation procedure, after certain time ablating,saline flow may be stopped (controlled via controller 18), andsubsequent impedance measurements may be taken. The collection of dataprior and during an ablation procedure may be processed by thecontroller 18 so as to provide an estimation of the state of the tissueduring an RF ablation procedure, thereby providing an operator (e.g.,surgeon) with an accurate indication success of the procedure.

FIG. 8 is a schematic illustration of the delivery of the applicatorhead 100 of FIG. 3 into a tissue cavity and subsequent ablation ofmarginal tissue according to methods of the present disclosure.

FIG. 9 is a perspective view of another embodiment of an applicator headcompatible with the tissue ablation device of FIG. 1. FIG. 10illustrates a method of deploying the applicator head of FIG. 9 into anexpanded configuration for delivery of RF energy to a target site forablation of marginal tissue. FIG. 11 illustrates different embodimentsof the outer surface of the applicator head of FIG. 9.

As shown, the applicator head may include a silicone-webbed mesh bodycomposed of an electrically conductive material. The mesh body may beself-expanding such that it is able to transition from a collapsedconfiguration, in which the mesh body is retracted within a portion ofthe shaft of the probe, to an expanded configuration upon deploymentfrom the shaft of the probe. Accordingly, the mesh body may include ashape-memory alloy, or similar material, so as to allow the mesh body totransition between collapsed and expanded configurations. The mesh bodyis further composed of an electrically conductive material and coupledto an RF generator, such that the mesh body is configured to deliver RFenergy. The mesh body may include webbing material that is applied via adipping method, for example, such that certain portions of the coatedmesh body can be exposed with a solvent, thereby enabling RF energy tobe delivered through the mesh to a tissue surface when the mesh body isin the expanded configuration and in direct contact with tissue. In someembodiments, to enhance the ablation, perforations along the webbing mayfurther allow fluid to be delivered to the outer surface of the meshbody. Since the mesh body is able to naturally expand, a fluid (e.g.,saline) can be delivered via a gravity-fed bag, and no pump is needed.In some embodiments, an inner balloon may be included within the meshbody so as to reduce the volume of energized saline.

FIG. 12 is a schematic illustration of the delivery of the applicatorhead of FIG. 9 into a tissue cavity and subsequent ablation of marginaltissue according to methods of the present disclosure.

Accordingly, a tissue ablation devices, particularly the applicatorheads described herein, may be well suited for treating hollow bodycavities, such as irregularly-shaped cavities in breast tissue createdby a lumpectomy procedure. The devices, systems, and methods of thepresent disclosure can help to ensure that all microscopic disease inthe local environment has been treated. This is especially true in thetreatment of tumors that have a tendency to recur.

As used in any embodiment herein, the term “controller”, “module”,“subsystem”, or the like, may refer to software, firmware and/orcircuitry configured to perform any of the aforementioned operations.Software may be embodied as a software package, code, instructions,instruction sets and/or data recorded on non-transitory computerreadable storage medium. Firmware may be embodied as code, instructionsor instruction sets and/or data that are hard-coded (e.g., nonvolatile)in memory devices. “Circuitry”, as used in any embodiment herein, maycomprise, for example, singly or in any combination, hardwiredcircuitry, programmable circuitry such as computer processors comprisingone or more individual instruction processing cores, state machinecircuitry, and/or firmware that stores instructions executed byprogrammable circuitry. The controller or subsystem may, collectively orindividually, be embodied as circuitry that forms part of a largersystem, for example, an integrated circuit (IC), system on-chip (SoC),desktop computers, laptop computers, tablet computers, servers, smartphones, etc.

Any of the operations described herein may be implemented in a systemthat includes one or more storage mediums having stored thereon,individually or in combination, instructions that when executed by oneor more processors perform the methods. Here, the processor may include,for example, a server CPU, a mobile device CPU, and/or otherprogrammable circuitry.

Also, it is intended that operations described herein may be distributedacross a plurality of physical devices, such as processing structures atmore than one different physical location. The storage medium mayinclude any type of tangible medium, for example, any type of diskincluding hard disks, floppy disks, optical disks, compact diskread-only memories (CD-ROMs), compact disk rewritables (CD-RWs), andmagneto-optical disks, semiconductor devices such as read-only memories(ROMs), random access memories (RAMs) such as dynamic and static RAMs,erasable programmable read-only memories (EPROMs), electrically erasableprogrammable read-only memories (EEPROMs), flash memories, Solid StateDisks (SSDs), magnetic or optical cards, or any type of media suitablefor storing electronic instructions. Other embodiments may beimplemented as software modules executed by a programmable controldevice. The storage medium may be non-transitory.

As described herein, various embodiments may be implemented usinghardware elements, software elements, or any combination thereof.Examples of hardware elements may include processors, microprocessors,circuits, circuit elements (e.g., transistors, resistors, capacitors,inductors, and so forth), integrated circuits, application specificintegrated circuits (ASIC), programmable logic devices (PLD), digitalsignal processors (DSP), field programmable gate array (FPGA), logicgates, registers, semiconductor device, chips, microchips, chip sets,and so forth.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, appearances of the phrases “in oneembodiment” or “in an embodiment” in various places throughout thisspecification are not necessarily all referring to the same embodiment.Furthermore, the particular features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments.

The terms and expressions which have been employed herein are used asterms of description and not of limitation, and there is no intention,in the use of such terms and expressions, of excluding any equivalentsof the features shown and described (or portions thereof), and it isrecognized that various modifications are possible within the scope ofthe claims. Accordingly, the claims are intended to cover all suchequivalents.

What is claimed is:
 1. A medical device comprising: a deployableapplicator head comprising an expandable outer balloon having aplurality of perforations and an expandable inner balloon configured tomaintain separation between an exterior surface of the inner balloon andan interior surface of the outer balloon thereby forming an interiorchamber; and a plurality of conductive wires disposed within theinterior chamber and configured to conduct energy to be carried by aconductive fluid passing through one or more of the plurality ofperforations, each of the plurality of conductive wires having asubstantially constant cross-section along its length.
 2. The medicaldevice of claim 1, further comprising a nonconductive handle and a lumenextending therethrough that is in fluid connection with the interiorchamber.
 3. The medical device of claim 1, wherein the inner balloon isconfigured to transition from a collapsed configuration to an expandedconfiguration in response to delivery of a fluid thereto and the outerballoon is configured to correspondingly transition from a collapsedconfiguration to an expanded configuration in response to expansion ofthe inner balloon.
 4. The medical device of claim 1, wherein, when in anexpanded configuration, one or more of the plurality of perforations isconfigured to allow passage of the conductive fluid from the interiorchamber to an exterior surface of the outer balloon.
 5. The medicaldevice of claim 4, wherein upon receipt of an electric current, each ofthe plurality of conductive wires is configured to conduct the energy tobe carried by the conductive fluid passing through one or more of theplurality of perforations for ablation of a tissue.
 6. The medicaldevice of claim 5, wherein the interior chamber is a plurality ofinterior chambers.
 7. The medical device of claim 6, wherein each of theplurality of conductive wires is disposed within a separate one of theplurality of interior chambers.
 8. The medical device of claim 7,wherein each of the plurality of conductive wires extends from aproximal end of the separate one of the plurality of interior chambersto a distal end of the separate one of the plurality of interiorchambers.
 9. The medical device of claim 7, wherein each of theplurality of conductive wires, or one or more sets of a combination ofconductive elements, is configured to independently receive anelectrical current from an energy source and independently conductenergy.
 10. The medical device of claim 9, wherein each of the pluralityof conductive elements is substantially aligned with one of theplurality of perforations.
 11. The medical device of claim 6, whereinthe inner balloon comprises an irregular exterior surface comprising aplurality of ridges or protrusions oriented along a longitudinal axis ofthe inner balloon.
 12. The medical device of claim 11, wherein theirregular exterior surface comprises the plurality of ridges, each pairof adjacent ridges of the plurality of ridges is configured to defineeach of the plurality of interior chambers.
 13. The medical device ofclaim 2, wherein the lumen is a first lumen and second lumen and theinner balloon is configured to receive a first fluid from the firstlumen and the outer balloon is configured to receive a second fluid fromthe second lumen.
 14. The medical device of claim 13, wherein at leastthe second fluid is the conductive fluid.
 15. The medical device ofclaim 13, further comprising a controller configured to independentlycontrol delivery of the first fluid and the second fluid to the innerballoon and to the outer balloon, respectively.
 16. A medical devicecomprising: a deployable applicator head comprising a self-expandablemesh body; an electrical element configured to deliver an electriccurrent to the self-expandable mesh body when in an expandedconfiguration; and a nonconductive handle having a lumen extendingtherethrough that is in connection with the self-expanding mesh body.17. The medical device of claim 16, wherein the lumen is configured todeploy the self-expandable mesh body into a predefined shape in theexpanded configuration and to receive the self-expandable mesh bodytherein in a collapsed configuration.
 18. The medical device of claim17, wherein the self-expandable mesh body is comprised of anelectrically conductive material and upon receipt of the electriccurrent, is configured to conduct and deliver the electrical current totarget tissue.
 19. The medical device of claim 18, wherein theself-expandable mesh body comprises a nonconductive webbed coatingcovering one or more portions of the self-expandable mesh body.
 20. Themedical device of claim 19, wherein the nonconductive webbed coatingcomprises a plurality of perforations configured to allow passage of afluid to an outer surface of the self-expandable mesh body when in theexpanded configuration.